This research project involves delineation of the chemical structures of human pituitary luteinizing hormone and follicle- stimulating hormone. These hormones are each composed of two subunits. Therefore, in essence, the proposal involves determination of amino acid sequences of four different proteins. Once the linear amino acid sequences are obtained, our attention will be focused on the structures of the carbohydrate moieties which are attached to the peptide chains of these proteins. Immunological characterization of these hormones together with the identification of antigenic determinants will be part of the study. The nature of binding of the two subunits will be studied by tryptophan fluorescence, modification of tyrosines, and other available means.